One of Wall Street's most venerable banks, Lehman Brothers, puts itself for sale after $4bn loss; with no buyer and refusal by US regulator to step in, declares bankruptcy. Merrill Lynch bought by Bank of America.

September 16

The US government announces $85bn rescue for insurance giant AIG.

September 19

Fearing total collapse in share prices, US securities and exchange commission bans short-selling - borrowing stock with the aim of selling it, then buying it back at a lower price. September 20-21

Treasury secretary Henry Paulson and fed chairman Ben Bernanke tell Congress to back a government buy-up of $700bn of bad mortgages. World stock markets soar.

George Bush addresses nation on TV on urgent need for Congress to pass $700bn bail-out of US money markets. John McCain surprisingly suspends his campaign. Barack Obama said neither need intervene, but later has to involve himself in the talks too. September 25

Washington Mutual becomes largest ever US bank failure. JPMorgan Chase buy it out for $1.9bn.September 26

Hopes that Congress would support bail-out in balance as some Republicans signal opposition. President says he remains confident.